New study sheds light on how upside-down jellyfish cause ‘stinging water’
Cassiopea jellyfish release toxin-filled mucus into the water that can lead to stinging, itching skin.

Scientists believe they may have solved the mystery of why coming close to upside-down jellyfish can cause irritating stings, without any direct contact with the creature.
Researchers have found that the Cassiopea jellyfish release toxin-filled mucus into the water that can lead to stinging, itching skin, a phenomenon which the team describe as “stinging water”.
Cheryl Ames, an associate professor at Tohoku University in Japan and one of the study authors, said: “This discovery was both a surprise and a long-awaited resolution to the mystery of stinging water.
“We can now let swimmers know that stinging water is caused by upside-down jellyfish, despite their general reputation as a mild stinger.”
Upside-down jellyfish live in warmer coastal regions around the world and can sometimes be seen in the shallow waters of the western Atlantic Ocean.